The present invention relates to an access site for a parenteral fluid delivery system and, more particularly, relates to an access site having a resilient, resealing member positioned in a housing cavity having parallel sidewalls and subjected to only axial compressive forces. Furthermore, the invention is directed to an access site of the type described herein including an axial perforation through the resilient resealing member which is especially useful with a blunt injection or connection device.
In general, parenteral fluids are often administered to patients from a syringe or other fluid container by a needle connection to a resealable access site of an I.V. administration set. A primary concern of the patient is that external contaminants don't enter the I.V. line through the injection site after the needle is removed. The access site must be guaranteed to reseal.
An equal anxiety among health care providers is that they are not exposed to infectious diseases, such as AIDS and hepatitis-B by accidental needle stick injuries. This concern by health care providers has led to an effort to reduce the number of sharp needles in the hospital environment. Central to this effort is the need to provide a reliable and resealable access site for parenteral fluids administered or connected by devices other than sharp needles. However, the access site must be versatile, since sharp needles will not be totally eliminated.
There are many known self-sealing injection sites usable with sharp needles. U.S. Pat. No. 4,416,661 titled "Injection Sites for Fluids" discloses one elastomeric plug held in a compression fit to resealably close a fluid entry port.
There are also known injection sites that are usable with blunt injection devices. For example, U.S. Pat. No. 4,197,848 discloses an injection site having a relatively thin molded sealing member that has an opening therethrough. A blunt injection device can be forced through the sealing member to place the injection device into fluid flow communication with the fluid flow path. Injection sites of this type use blunt injection devices and reduce the risk of needle stick for the health care provider.
It is important that the parenteral injection site reseal with enough force that viral or bacterial contaminants do not enter the parenteral flow path and infect the patient. Furthermore, it is desireable that parenteral fluids do not leak from the parenteral administration system.
A recent effort to provide a pre-slit injection site which can be used with a variety of solutions and over a range of fluid pressures is disclosed in published PCT Application No. PCT/US89/00273 (WO 89/06553) titled "Pre-Slit Injection Site and Tapered Cannula". This injection site incorporates a housing having an annular, tapered interior surface with the diameter of the tapered surface decreasing with increasing distance away from the housing opening. A cylindrical sealing member is positioned in the tapered interior surface so as to generate resealing radial forces increasing in value from an axial position adjacent the exterior peripheral surface of the injection site to a greater value interior from the peripheral surface. FIG. 27 of the application also discloses an alternate, non-tapered embodiment which is described as providing "compression to create a seal against pressure and a void region to accommodate deformed portions of the sealing member material only when the material is deformed or displaced by a blunt cannula piercing member."
All of the above described injection sites are deficient in providing at least one or more of a balance of reliable sealing around an inserted cannula as well as resealing after the cannula is removed, straightforward assembly and manufacture (without the need for void areas for example), ease of use with both sharp or blunt injection devices, reasonable active use life, sufficient engaging force to prevent inadvertent withdrawal of the cannula, and a minimal tendency to kickback the injection device out of the reseal member.
The present invention is directed to an alternative access site which is believed to provide advantages over the previously described unslit and pre-slit injection sites.